1. Field of the Invention
The present invention relates to a rotary device of a generator or motor.
2. Background of the Related Art
As one prior art, there is proposed Korean Patent Registration No. 597191 entitled ‘rotor of generator and motor’ as filed by the same applicant as this invention wherein the rotor is provided with a plurality of magnetic flux-increasing magnets for increasing magnetic flux therein, thereby improving the generation efficiency of the generator or motor.
In the prior art, however, the rotor is skewed at a given angle so as to decrease a cogging torque causing vibration and noise in the generator or motor.
In this case, actually, the desired skew is not formed easily because of the attractive force or repulsive force between the upper and lower permanent magnets and the rotation of the rotor, and further, it is not easy to keep the skew designed initially.
Moreover, in the conventional rotary devices wherein the skew is provided to the rotor or the stator, or both of them, it is not easy to keep the skew designed initially, such that there is a problem in that the cogging torque causing noise and vibration cannot be sufficiently decreased only with the skew designed initially.
FIG. 1 is a view showing the lines of magnetic force generated from permanent magnets according to the conventional practice, wherein the lines of magnetic force are generated by a plurality of N-polar and S-polar permanent magnet groups.
As shown in FIG. 1, it can be appreciated that lots of magnetic flux leaks, such that the lines of magnetic force formed on the rotor body do not form a smooth curve and are substantially significantly bent. According to the conventional practice, therefore, there is a problem that the magnetic force is increased, but the cogging torque is not sufficiently decreased, thereby making the generation efficiency deteriorated.
Generally, a generator is a device that generates an electromotive force by electromagnetic induction to convert a mechanical energy into an electrical energy. Most of generators are rotators, and recently, linearly moving generators are developed.
The generator requires magnets producing a magnetic field and a conductor generating an electromotive force, and in this case, any one of the magnets and the conductor should be moved. A generator in which the conductor stops and the magnetic field rotates is a revolving field type, and contrarily, a generator in which the conductor rotates and the magnetic field stops is a revolving armature type.
As another prior art, there has been disclosed Korean Utility Model Registration No. 0182495 wherein a stator is of a ring shape, and when the plurality of stators are cut by means of press processing, there is a problem that the materials formed between the adjacent stators and at the inside of the ring are unnecessarily consumed.
Moreover, since the electric wires are wound around the stator of a generator or a motor, the stator causes electromagnetic induction together with the rotator, and in this case, harmonics may be generated.